Collections that feature the Chicago area. Chicago is the largest city in the state of Illinois. It is the financial, business, and cultural capital of the Midwest. Founded in 1833 at the site of a portage between the Great Lakes and the Mississippi River watershed, it soon became a transportation hub of North America. Since the first steel-framed high-rise building of the world was constructed in the city in 1885, Chicago has been known for its skyscrapers, and today boasts the world's tallest skyline. Many high-rise buildings are located in the downtown area along the lakefront and the Chicago River. Chicago is also known as "The Windy City," "The Second City," "Chi Town," "The City that Works". http://egov.cityofchicago.org